1. Technical Field
The present disclosure relates generally to a surgical tool assembly for manipulating and/or applying fasteners to tissue. More specifically, the present disclosure relates to a surgical tool assembly having a pair of jaws including a unique approximation mechanism to facilitate improved clamping and manipulation of tissue.
2. Background of Related Art
Surgical staplers and tool assemblies for clamping tissue between opposed jaw structure of a tool assembly and thereafter fastening the clamped tissue are well known in the art. These devices may include a knife for incising the fastened tissue. Such staplers having laparoscopic or endoscopic configurations are also well known in the art. Examples of endoscopic surgical staplers of this type are described in U.S. Pat. Nos. 6,330,965, 6,250,532, 6,241,139, 6,109,500 and 6,079,606, all of which are incorporated herein by reference in their entirety.
Typically, such staplers include a tool member or assembly having a pair of jaws including a staple cartridge for housing a plurality of staples arranged in at least two laterally spaced rows and an anvil which includes a plurality of staple forming pockets for receiving and forming staple legs of the staples as the staples are driven from the cartridge. The anvil and cartridge are pivotally supported adjacent each other and are pivotable in relation to each other between open and closed positions. In use, tissue is positioned between the jaws in the open position and the jaws are pivoted to the closed position to clamp tissue therebetween.
One problem associated with conventional staplers and tool assemblies is that as the anvil and cartridge pivot in relation to each other, closure occurs first at the proximal end of the jaws and thereafter at the distal end of the jaws. This sequence of jaw closure has the effect of moving tissue positioned between the jaws towards the distal end of the jaws, thus, forcing tissue from the jaws.
During laparoscopic or endoscopic procedures, access to a surgical site is achieved through a small incision or through a narrow cannula inserted through a small entrance wound in a patient. Because of the limited area available to access the surgical site, endoscopic staplers are sometimes used to grasp and/or manipulate tissue. Conventional staplers having an anvil or cartridge mounted to a fixed pivot point which are pivotable to a closed position are not particularly suited for grasping tissue because only a limited clamping force is produced at the distal end of the jaws.
Accordingly, a need exists for an endoscopic surgical stapling tool member or assembly having pivotal jaws which can be operated to effectively grasp, manipulate and/or fasten tissue, including with the end of the jaws, without, or while minimizing, distal movement of the tissue positioned between the jaws.